U.S. patent number 6,692,375 [Application Number 10/039,863] was granted by the patent office on 2004-02-17 for golf club.
This patent grant is currently assigned to K.K. Endo Seisakusho. Invention is credited to Nobuo Abe.
United States Patent |
6,692,375 |
Abe |
February 17, 2004 |
Golf club
Abstract
A golf club where the center axis of a shaft is precisely
aligned to that of a head when connecting the shaft to the head,
with improved bonding strength therebetween. A shaft insertion hole
7 is formed on a distal end face 6A of a hosel 6 of a head 2. A
shaft 3 is inserted into the hole 7 and is bonded thereto with an
adhesive 10. An enlarged portion 8 is formed, which is in the form
of a chamfered portion with a peripheral slope formed at an opening
portion of the hole 7. The enlarged portion 8 is provided with a
ring body 11, while the shaft 3 is inserted into a through-hole 12
formed in the ring body 11. As the shaft 3 is inserted to penetrate
through the through-hole 12 of the ring body 11, the shaft 3 is
held by the ring body 11 in place within the enlarged portion 8 so
that a uniform gap between a distal portion 3A of the shaft 3 and
the hole 7 is insured and the thickness of an adhesive can be
distributed uniformly. Also, various angles of a golf club such as
a lie angle can be formed accurately.
Inventors: |
Abe; Nobuo (Tsubame,
JP) |
Assignee: |
K.K. Endo Seisakusho
(Niigata-ken, JP)
|
Family
ID: |
18853180 |
Appl.
No.: |
10/039,863 |
Filed: |
October 26, 2001 |
Foreign Application Priority Data
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Dec 19, 2000 [JP] |
|
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2000-386009 |
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Current U.S.
Class: |
473/310 |
Current CPC
Class: |
A63B
60/54 (20151001); A63B 53/02 (20130101) |
Current International
Class: |
A63B
53/02 (20060101); A63B 59/00 (20060101); A63B
053/02 () |
Field of
Search: |
;473/310,308,309 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Blau; Stephen
Attorney, Agent or Firm: Quarles & Brady LLP
Claims
What is claimed is:
1. A golf club which comprises: a head having a hosel; a shaft
insertion hole provided on a distal end face of said hosel; and a
shaft fitted into said shaft insertion hole and bonded thereto with
an adhesive, wherein said shaft insertion hole is formed with an
enlarged portion formed in an opening portion thereof, while a ring
body with a through-hole formed therethrough is provided in said
enlarged portion so that said shaft is insertable and penetratable
therethrough, wherein said enlarged portion is provided in the form
of a stepped portion, while said ring body comprises: a flange
portion to be fitted into said enlarged portion; a cylindrical
portion to be fitted into said shaft insertion hole, said
cylindrical portion integrally extending from the flange portion;
and wherein said golf club further comprises a ferrule which is
provided above the distal end face of said hosel and penetrated by
said shaft, and wherein a top surface of said ring body is anchored
by the ferrule.
2. A golf club according to claim 1, wherein said ring body is made
of rubber or plastic.
3. A golf club according to claim 2, wherein said ring body is made
of fiber reinforced plastic.
4. A golf club according to claim 1, wherein said ring body is made
of rubber or plastic.
5. A golf club which comprises: a head having a hosel; a shaft
insertion hole provided on a distal end face of said hosel, said
shaft insertion hole being formed with an enlarged portion formed
in an opening portion thereof; a ring body with a through-hole
formed therethrough, said ring body being provided in said enlarged
portion so that said shaft is insertable and penetratable
therethrough; and a shaft fitted into said shaft insertion hole and
bonded thereto with an adhesive, wherein said enlarged portion is
provided in the form of a chamfered portion so that an outer
peripheral face of said ring body is fitted into said enlarged
portion, wherein said ring body is nearly cone-shaped, including a
peripheral face formed into a reverse-tapered shape so as to be
fitted into said enlarged portion; and a through-hole formed
through a center of said ring body for inserting a distal portion
of said shaft therethrough; wherein said golf club further
comprises a ferrule which is provided above the end face of said
hosel and penetrated by said shaft, wherein a top surface of said
ring body is anchored by the ferrule in such a manner that the top
surface thereof is closed by a bottom of said ferrule, wherein said
ring body is made of rubber or plastic, and wherein said ring body
is made of fiber reinforced plastic.
Description
BACKGROUN OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club.
2. Description of the Related Art
Hitherto when a golf club comprising a head and a shaft is
assembled, the shaft is processed rough on the surface of a distal
portion thereof, and is fitted with a truncated-cone-shaped,
socket-like ferrule, while protruding the shaft itself from the
ferrule by a suitable length to be bonded. Thereafter, epoxy-based
resin or the like is normally applied to the portion of a shaft to
be bonded so that the shaft is fixed to the head. The distal
portion of the shaft has a diameter which is about 0.1 mm smaller
than an inside diameter of a shaft insertion hole formed in a
hosel, in order that an adhesive may be ensured to be present
between the hosel and the shaft. Although a gap between the shaft
insertion hole in the hosel and the shaft is very narrow, it is
very difficult to allow the central axis of the shaft to precisely
align with that of the hosel due to this narrow gap, and thus the
shaft occasionally is fitted at an offset position and/or inclined
toward a certain direction. As a result, such golf club is
subjected to changes in angles including loft, lie and face angles
after assembling, even though these angles were each in accordance
with designed values at the time of the completion of the head.
Whilst an adhesive should desirably be applied uniformly to an area
for adhesion and then be hardened because one can obtain the
highest strength by doing so, there is the possibility, if the gap
is not uniform, that the adhesive strength might be reduced and the
head get detached from the shaft during the use of the golf
club.
For this type of a golf club, Japanese Un-Examined Patent
Publication Number 10-314345 discloses a golf club in which a
distal end of a shaft is fitted to a hosel in such a manner that
the hosel is formed with a stepped peripheral surface, through
which the distal end of the shaft is inserted from the outside into
the hosel, while a ring made of plastic is bonded to said stepped
peripheral surface so that the separation of the shaft from the
head may be prevented.
According to the above prior art, the improvement of the joint
strength between the head and the shaft is aimed at, using the
ring, which, however, has a drawback that it is often very
difficult to adjust so as to have the central axis of the shaft
precisely align to that of the head, when connecting the shaft to
the head, and thus there is a probability that angles including
loft, lie and face angles are subjected to delicate changes after
the head and the shaft are assembled together.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
golf club in which the axis of a shaft can be precisely aligned to
that of a head when connecting them to each other, to thereby
prevent loft, lie, face angles and etc of the club head from
deviating from designed values.
It is another object of the present invention to provide a golf
club with a high adhesive strength between the head and the
shaft.
To attain the above objects, there is provided, according to a
first aspect of the present invention, a golf club which comprises:
a head having a hosel; a shaft insertion hole provided on a distal
end face of said hosel; and a shaft fitted into said shaft
insertion hole and bonded thereto with an adhesive, wherein said
shaft insertion hole is formed with an enlarged portion formed in
an opening portion thereof, while a ring body with a through-hole
formed therethrough is provided in said enlarged portion so that
said shaft may be inserted and penetrate therethrough.
According to the first aspect, the shaft is inserted into the shaft
insertion hole while being guided by the ring body.
According to a second aspect of the present invention, there is
provided a golf club as set forth in the first aspect, wherein said
enlarged portion is provided in the form of a chamfered portion or
a stepped portion so that an outer peripheral face of said ring
body is fitted into said enlarged portion.
According to the structure of the second aspect, as the outer
peripheral face of the ring body is fitted into and fixed by the
chamfered portion or the stepped portion, the shaft can be guided
well through said ring body.
According to a third aspect of the present invention, there is
provided a golf club according to any of the foregoing aspect,
wherein said ring body is made of rubber or plastic.
Accordingly, the ring body is elastically deformable at the time of
striking a golf ball.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will be
apparent to those skilled in the art from the following description
of the preferred embodiments of the invention, wherein reference is
made to the accompanying drawings, of which:
FIG. 1 is a partially cutaway front view showing a golf club
according to a first embodiment of the present invention, while
FIG. 1a is a partially enlarged section thereof.
FIG. 2 is an exploded perspective view showing a golf club
according to the first embodiment of the present invention.
FIG. 3 is a partially cutaway front view showing a golf club
according to a second embodiment of the present invention, while
FIG. 3a is a partially enlarged section thereof.
FIG. 4 is an exploded perspective view showing a golf club
according to the second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereunder is a description of the embodiments of the present
invention with reference to the appended drawings.
As shown in FIG. 1 and FIG. 2 showing a first embodiment, a golf
club 1 comprises a head 2 and a shaft 3 connected to the head 2,
said shaft 3 being formed from metal such as stainless steel or
from carbon. The head 2 is provided with a face 4 for striking a
ball on a front, a sole 5 on a bottom and a hosel 6 for connecting
a shaft 3 thereto on one side, said hosel 6 extending obliquely
upward. A shaft insertion hole 7 is defined through a distal end
face 6A of the hosel 6 to the sole 5, aligning with the center axis
of the hosel 6. The diameter A of the hole 7 that is circular in
plane view is formed a little larger than the diameter B of the
distal portion 3A of the shaft 3. The opening of the hole 7 is
formed with an enlarged portion 8 having a larger diameter C than
the diameter A. The enlarged portion 8 is formed into a
reverse-tapered shape as a chamfered portion. The shaft 3 with a
grip 9 at its proximal end allows the distal portion 3A thereof to
be inserted into the hole 7 to be bonded with an adhesive 10.
A ring body 11 which is circular in plane view is provided in the
enlarged portion 8 of the hole 7. The ring body 11 is nearly
cone-shaped, including a peripheral face 11A formed into a
reverse-tapered shape so as to be fitted into the enlarged portion
8; and a through-hole formed through a center thereof for inserting
the distal portion 3A therethrough. The ring body 11 is formed from
rubber or plastic, preferably fiber reinforced plastic. The
strength of the ring body 11 may desirably be set to lower than
that of the head 2 and the shaft 3. The diameter D of the
through-hole 12 is formed nearly equal to or slightly smaller than
the diameter B of the distal portion 3A of shaft 3 so that the
distal portion 3A may be fitted into the through-hole 12. Further,
a socket-like ferrule 13 is provided on the distal end face 6A of
the hosel 6, so as to serve as an auxiliary tube for connection.
This ferrule 13 is a truncated-cone-shaped so that a diameter at
its bottom 13A may be nearly equal to that of the aforesaid distal
end face 6A, including a through-hole 14 formed through the center
thereof for fitting the shaft 3 thereinto, while a top portion of
the aforesaid ring body 11 fixedly engages with the bottom portion
13A in such a manner that the top portion of the ring body 11 is
closed by the bottom portion 13A. In the meantime, reference
numeral 16 denotes filler for filling up a gap between the distal
portion 3A and the sole 5 in the hole 7.
Next is a description of how a golf club with the aforementioned
structure is assembled. The shaft 3 is preliminarily processed
rough on the surface of the distal portion 3A, and then fitted into
the ferrule 13 with the shaft 3 protruding from the ferrule 13 by a
suitable length to be bonded. Further, the distal portion 3A is
fitted into the ring body 11. At this moment, the distal portion 3A
is fitted into the ring body 11 while the top face of the ring body
11 fixedly engages with the bottom 13A of the ferrule 13, being
closely contacted by the same. Then, an adhesive is applied to the
hole 7 and the distal portion 3A, which is inserted into the hole
7. At this moment, as the peripheral face 11A of the ring body 11
is fitted to the enlarged portion 8, the center axis of the shaft 3
can be aligned with the center axis X of the hole 7. Under such
condition, the adhesive is allowed to be present between the shaft
3 and the hole 7 to thereby bond them each other.
When assembling a golf club of the invention in the foregoing
manner, the ring body 11, which is penetrated by the distal portion
3A, is fitted into the enlarged portion 8 formed on the distal end
face 6A of the hosel 6, so that the gap between the distal portion
3A of the shaft 3 and the hole 7 can be formed uniformly, due to
the ring body 11. Further, as the distal portion 3A is fitted into
the through-hole 12 of the ring body 11, the distal portion 3A is
guided and held in place so that the center axis of shaft 3 is more
easily aligned with the center axis X of the hole 7.
On the other hand, although a strong load is applied to the joint
of the shaft 3 and the hosel 6, i.e., a portion of the shaft 3
located at the distal end face 6A of the hosel 6 when a golf player
swings the golf club 1 and strikes a golf ball (not shown in the
drawings) on the face 4, the impact developed at the portion can be
moderated owing to the ring body 11 made of plastic, specifically
fiber reinforced plastic, acting as a buffer.
As is apparent from the foregoing, according to the foregoing
embodiment, there is provided a golf club which comprises: the head
2 having the hosel 6; the shaft insertion hole 7 provided on the
distal end face 6A of the hosel 6; and the shaft 3 fitted into the
shaft insertion hole 7 and bonded thereto with an adhesive, wherein
said shaft insertion hole 7 is formed with the enlarged portion 8
provided in the form of the chamfered portion defining an inclined
peripheral surface in said shaft insertion hole 7, while the ring
body 11 with the through-hole 12 formed therethrough is provided in
the enlarged portion 8 so that the shaft 3 may be inserted and
penetrate therethrough.
Thus, as the ring body 11 is provided in the enlarged portion 8,
serving as a countersink or the like preformed in drilling said
hole 7 in said head 2, there is no clearance or gap formed in the
enlarged portion 8, thus improving the joint strength. Further, as
the shaft 3 is held by the ring body 11 in position due to the
shaft 3 penetrating the through-hole 12 of the ring body 11, the
uniform gap between the distal portion 3A of the shaft 3 and the
hole 7 is insured so that the thickness of the adhesive 10 can be
uniform, thus enabling the adhesion strength to be distributed
uniformly. Also, lie, loft, face angles and the like of a golf club
can be formed accurately. Furthermore, as the shaft 3 can be held
by the ring body 11, the head 2 and the shaft 3 can be kept
stationary until they are bonded by the adhesive 10 at the time of
assembly.
Moreover, as said enlarged portion 8 is formed by the chamfered
portion and the peripheral face 11A of said ring body 11 is fitted
into the enlarged portion 8, the ring body 11 can be firmly fitted
into the enlarged portion 8 so that more uniform gap between the
shaft 3 and the hole 7 as well as more uniform thickness of the
adhesive 10 can be ensured.
Also, as the ring body 11 is made of rubber or plastic, the impact
developed at the time of striking a golf ball is absorbed by the
ring body 11 due to the elasticity of rubber or plastic, thereby
enabling the improving of the anti-impact strength of the shaft 3.
Specifically, when the ring body 11 is made of fiber reinforced
plastic, the strength thereof can be improved further so that the
strength against impact at the joint of the shaft 3 can be improved
still further.
Still also, as the upper surface of the ring body 11 is anchored by
the ferrule 13 provided on the distal end face 6A of the hosel 6
and penetrated by the shaft 3, the ring body 11 is surrounded by
the shaft 3, the enlarged portion 8 and the bottom 13A of the
ferrule 13, so that the impact developed at the time of striking
can be transferred to the shaft 3 not only via the shaft 3 side but
also via the ferrule 13 side when it is transferred to the shaft 3
via the face 4 and the hosel 6, thereby enabling the strength
against the impact to be improved.
Moreover, as the distal portion 3A of the shaft 3 penetrates the
through-hole 12 of the ring body 11, the ring body 11 can be held
together relative to the distal portion 3A. Therefore, when the
ring body 11 and the ferrule 13 are integrally attached to the
shaft 3, and the distal end portion 3A of the shaft 3 is inserted
into the hole 7, the ring body 11 can be automatically fitted into
the enlarged portion 8, thus improving assembling efficiency.
uniformly. Also, lie, loft, face angles and the like of a golf club
can be formed accurately. Furthermore, as the shaft 3 can be held
by the ring body 22, the head 2 and the shaft 3 can be kept
stationary until they are bonded by the adhesive 10 at the time of
assembly.
Specifically, the second embodiment is advantageous in that as the
ring body 22 comprises the flange portion 23 fitted into the
enlarged portion 21 and the cylindrical portion 24 fitted into the
shaft insertion hole 7, said cylindrical portion 24 extending
integrally from the flange portion 23, two fitting portions are
provided so that the ring body 22 can be accurately fitted into the
hole 7 of the hosel 6.
In the meantime, the present invention should not be limited to the
above-mentioned embodiments, but various modifications are possible
within the scope of the invention.
* * * * *